Examining two major mental illnesses that are, loosely, grouped by mood and thought.
Schizophrenia is regarded as an illness associated with thought disorder.
Bipolar is regarded as a mood disorder.
Both conditions can lead to a psychotic break and behavioral disturbance. Hallucinations can occur in both.
Bipolar is characterized by depression with the occurrence of, at least, one episode of mania.
Schizophrenia is characterized by phases. An active phase, where psychotic symptoms peak and the negative phase, when the personality has little affect.
Given that both cause behavioral problems and changes to mood. That psychosis is based on false beliefs, and beliefs are thoughts. What is the scientific and the psychiatric basis for regarding schizophrenia as a thought disorder and bipolar a mood disorder?